The Ottoman Bank (Turkish: Osmanlı Bankası), known from 1863 to 1925 as the Imperial Ottoman Bank (French: Banque Impériale Ottomane, Ottoman Turkish: بانق عثمانی شاهانه) and correspondingly referred to by its French acronym BIO, was a bank that played a major role in the financial history of the Ottoman Empire. By the early 20th century, it was the dominant bank in the Ottoman Empire, and one of the largest in the world.